§1.1 Field of the Invention
The present invention concerns antennas. In particular, the present invention concerns providing an improved slot antenna having a desirable radiation characteristic and an improved antenna array with simplified impedance matching.
§1.2 Background Information
Slot or aperture antennas have non-ideal radiation characteristics for various applications. Therefore, it would be useful to provide a slot antenna with an improved radiation characteristic, such as an isotropic or substantially isotropic radiation characteristic in a hemispherical space, with no radiation in the other half space.
Further, the scanning performance of a large planar antenna array normally depends on both the elevation angle (θ) and the azimuth angle (φ). This makes it practically very difficult to “match” its electronic feeding circuits in order to perform in a desired manner for scanning in all directions in θ and φ. There are simply too many directions in a 3D space for complex circuit optimizations to be implemented. Therefore, it would be useful to simplify the optimization of antenna arrays.